166 lines
4.1 KiB
C
166 lines
4.1 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* Copyright (C) 2019 Bootlin
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* Author: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
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*/
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#include <linux/err.h>
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#include <linux/gpio/driver.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/of_address.h>
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#include <linux/platform_device.h>
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#include <linux/regmap.h>
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#include <linux/mfd/syscon.h>
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#define LOGICVC_CTRL_REG 0x40
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#define LOGICVC_CTRL_GPIO_SHIFT 11
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#define LOGICVC_CTRL_GPIO_BITS 5
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#define LOGICVC_POWER_CTRL_REG 0x78
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#define LOGICVC_POWER_CTRL_GPIO_SHIFT 0
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#define LOGICVC_POWER_CTRL_GPIO_BITS 4
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struct logicvc_gpio {
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struct gpio_chip chip;
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struct regmap *regmap;
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};
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static void logicvc_gpio_offset(struct logicvc_gpio *logicvc, unsigned offset,
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unsigned int *reg, unsigned int *bit)
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{
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if (offset >= LOGICVC_CTRL_GPIO_BITS) {
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*reg = LOGICVC_POWER_CTRL_REG;
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/* To the (virtual) power ctrl offset. */
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offset -= LOGICVC_CTRL_GPIO_BITS;
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/* To the actual bit offset in reg. */
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offset += LOGICVC_POWER_CTRL_GPIO_SHIFT;
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} else {
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*reg = LOGICVC_CTRL_REG;
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/* To the actual bit offset in reg. */
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offset += LOGICVC_CTRL_GPIO_SHIFT;
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}
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*bit = BIT(offset);
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}
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static int logicvc_gpio_get(struct gpio_chip *chip, unsigned offset)
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{
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struct logicvc_gpio *logicvc = gpiochip_get_data(chip);
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unsigned int reg, bit, value;
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int ret;
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logicvc_gpio_offset(logicvc, offset, ®, &bit);
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ret = regmap_read(logicvc->regmap, reg, &value);
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if (ret)
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return ret;
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return !!(value & bit);
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}
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static void logicvc_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
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{
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struct logicvc_gpio *logicvc = gpiochip_get_data(chip);
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unsigned int reg, bit;
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logicvc_gpio_offset(logicvc, offset, ®, &bit);
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regmap_update_bits(logicvc->regmap, reg, bit, value ? bit : 0);
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}
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static int logicvc_gpio_direction_output(struct gpio_chip *chip,
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unsigned offset, int value)
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{
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/* Pins are always configured as output, so just set the value. */
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logicvc_gpio_set(chip, offset, value);
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return 0;
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}
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static struct regmap_config logicvc_gpio_regmap_config = {
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.reg_bits = 32,
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.val_bits = 32,
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.reg_stride = 4,
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.name = "logicvc-gpio",
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};
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static int logicvc_gpio_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct device_node *of_node = dev->of_node;
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struct logicvc_gpio *logicvc;
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int ret;
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logicvc = devm_kzalloc(dev, sizeof(*logicvc), GFP_KERNEL);
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if (!logicvc)
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return -ENOMEM;
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/* Try to get regmap from parent first. */
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logicvc->regmap = syscon_node_to_regmap(of_node->parent);
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/* Grab our own regmap if that fails. */
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if (IS_ERR(logicvc->regmap)) {
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struct resource res;
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void __iomem *base;
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ret = of_address_to_resource(of_node, 0, &res);
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if (ret) {
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dev_err(dev, "Failed to get resource from address\n");
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return ret;
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}
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base = devm_ioremap_resource(dev, &res);
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if (IS_ERR(base))
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return PTR_ERR(base);
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logicvc_gpio_regmap_config.max_register = resource_size(&res) -
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logicvc_gpio_regmap_config.reg_stride;
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logicvc->regmap =
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devm_regmap_init_mmio(dev, base,
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&logicvc_gpio_regmap_config);
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if (IS_ERR(logicvc->regmap)) {
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dev_err(dev, "Failed to create regmap for I/O\n");
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return PTR_ERR(logicvc->regmap);
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}
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}
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logicvc->chip.parent = dev;
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logicvc->chip.owner = THIS_MODULE;
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logicvc->chip.label = dev_name(dev);
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logicvc->chip.base = -1;
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logicvc->chip.ngpio = LOGICVC_CTRL_GPIO_BITS +
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LOGICVC_POWER_CTRL_GPIO_BITS;
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logicvc->chip.get = logicvc_gpio_get;
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logicvc->chip.set = logicvc_gpio_set;
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logicvc->chip.direction_output = logicvc_gpio_direction_output;
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return devm_gpiochip_add_data(dev, &logicvc->chip, logicvc);
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}
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static const struct of_device_id logicivc_gpio_of_table[] = {
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{
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.compatible = "xylon,logicvc-3.02.a-gpio",
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},
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{ }
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};
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MODULE_DEVICE_TABLE(of, logicivc_gpio_of_table);
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static struct platform_driver logicvc_gpio_driver = {
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.driver = {
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.name = "gpio-logicvc",
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.of_match_table = logicivc_gpio_of_table,
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},
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.probe = logicvc_gpio_probe,
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};
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module_platform_driver(logicvc_gpio_driver);
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MODULE_AUTHOR("Paul Kocialkowski <paul.kocialkowski@bootlin.com>");
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MODULE_DESCRIPTION("Xylon LogiCVC GPIO driver");
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MODULE_LICENSE("GPL");
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